The invention relates to a guide method for guiding a device that is designed to insert elements into the ground in order to make a structure, and it relates in particular to a guide method for guiding a device of the type described in patent application EP 0 803 609 for inserting baseplates for making a railway track, the device enabling baseplates to be inserted into concrete at given positions that are accurate to within less than 1 millimeter (mm). The invention also relates to a device for inserting elements into the ground that implements such a guide method.
A device for inserting baseplates into concrete enabling a railway track to be made quickly and at low cost is known from document EP 0 803 609. However, in order to be effective, such a baseplate insertion device requires the insertion device itself to be put into place accurately so as to obtain an accurate position for each baseplate. At present, the insertion device is used in association with on-site guide rails, previously installed along the path to be followed by the railway track relative to fixed references and as determined by surveying, and serving as a reference for positioning the baseplate insertion device.
However, the prior placement of the on-site guide rails along the path of the railway track presents the drawback of being lengthy and time consuming, and thus of considerably slowing down the construction of the railway track. In addition, in order to obtain good accuracy in positioning the insertion device, it is necessary for the ground supporting the on-site guide rails to be properly stabilized in order to prevent said guide rails from moving under the pressure of the bearing points used by the insertion device to define its position. In addition, the work commonly carried out on such a site is capable of accidentally displacing the guide rails.
The object of the present invention is thus to remedy those drawbacks by proposing a guide method enabling an insertion device for inserting elements into the ground to be positioned accurately and quickly, the method being simple to implement and of low cost.
To this end, the invention provides a guide method for guiding a device that is designed to insert elements into the ground in order to make a structure, the method comprising the following steps:
establishing topographical points and determining the coordinates of these points in an X, Y, Z frame of reference;
putting a measuring station in place in the vicinity of the structure and determining the X, Y, Z position of the measuring station with reference to one or more topographical points;
determining, by means of the measuring station, the distance and the angle between the insertion device for inserting elements into the ground and the measuring station;
calculating the position of the insertion device by means of the measured distance and the measured angle, and the known position of the measuring station; and
displacing the insertion device so that the elements are in register on the insertion axis with given positions where the elements are to be inserted into the ground.
In particular embodiments, the guide method of the invention can comprise one or more of the following characteristics, taken in isolation, or in any technically feasible combination:
the measuring station includes an optical-measuring method by means of a laser cooperating with reflectors carried by the insertion device;
surveys are performed at various reference points distributed along the structure, and as the insertion device advances, the measuring station is displaced over the survey point maximizing the calculation accuracy that can be obtained by means of the measuring station;
the distance between two successive survey points lies in the range 50 meters (m) to 100 m so as to obtain accuracy to within less than 1 mm in measuring the positions of the elements inserted into the ground;
displacement of the insertion device is controlled by an on-board controller connected to an on-board computer, as a function of distance and orientation data communicated to the computer at each instant by the measuring station, so as to bring the elements supported by the insertion device substantially into register on the insertion axis with given positions whose coordinates are stored in a memory of the computer;
the insertion device includes an arm supporting the elements, the arm being driven in translation and in rotation along three axes that are mutually orthogonal, the movement of the arm being controlled by the computer so as to bring the elements accurately into register on the insertion axis with the given positions; and
the structure is a railway track, and the elements are baseplates designed to support a rail, the baseplates being inserted into a concrete slab before it sets.
The invention also provides an insertion device for inserting at least one element into the ground, the device implementing the above-described guide method, and including at least one reflector designed to reflect an emission from a measuring station and enabling the distance and the angle between the reflector and the measuring station to be determined accurately.
In particular embodiments, the insertion device of the invention for inserting elements into the ground can comprise one or more of the following characteristics, taken in isolation, or in any technically feasible combination:
the device includes an arm driven in translation and in rotation on three axes that are mutually orthogonal, the arm supporting the elements intended to be inserted into the ground and including reflectors enabling the positions in three dimensions of the arm and of the elements to be inserted into the ground to be known by means of the measuring station;
the device includes driving and/or steerable wheels or crawler tracks to constitute a vehicle that can move autonomously, the chassis of the vehicle itself being fitted with a reflector;
the vehicle includes a computer receiving data from the measuring station and calculating the position of the vehicle and of the arm, the computer sending signals to the controller in order to control displacement of the vehicle and of the arm so that the elements are inserted into the ground at predetermined locations; and
said elements are baseplates designed to support a railway rail, said baseplates being inserted into a concrete slab before it sets.